Plant air compressor efficiency - not air compressor
WAREHOUSE ONE AIR SUPPLY
By Larry Bush
Summary: "Plant air compressor efficiency is commonly effected by other factors than the air compressor it's self. Larry offers some insight in this article about his air equipment and lines."
I have a rough sketch of the air system in the warehouse 1 area. This sketch clearly shows the reason why we keep having air problems. The air line supplying 90% of the air using equipment is only one inch pipe. There are approximately 29 pieces of air using equipment that are tapped off the one inch pipe coming out of the main warehouse 1 air supply line.
No matter that the air pressure on the main line is 100# psi. While running, by the time the air is coming out of the yellow, air surge tank, it is down to 78# psi. Then, by the time it gets to the Videojets, the pressure is down to 62# psi. A slight drop trips the air switch at 60#psi.
The cost of installing a larger surge tank feeder pipe (2 inch) and larger supply headers (2 inch) from the surge tank to the equipment risers could be easily justified by the reduction in production stoppages, equipment repair costs, and not being required to brightstack so much product.
The low air pressure and volume could be causing problems on the other air using equipment. The other stackers, casers and sleevers may be partially air starved and the problems show up as when a pusher doesn't push fast enough or doesn't push all the way.
There are formulas and tables in Mechanical Engineering Handbooks that detail the exact size of piping needed to supply a given volume of air at a required pressure for air using equipment. We are using a tremendous amount of air in Warehouse 1 and the piping is grossly undersized. Even with the booster air compressor, the volume and pressure are restricted by the small size of the piping.
A temporary fix for the videojets would be, ½" air hoses tapped from the riser at a point closer to the header and then to the videojets (lines 1,2,3,4). This job could be carried out during a down day for 4 oz. and the final upgrades could be carried out during the off season.
The air supply dryers and water separators at the air compressors are not removing all the water from the air at the points of use. The air system needs to be surveyed and evaluated in regards to the placement of area and local air dryers and water and sediment separators in the air system.
An increasing number of air using equipment breakdowns with a resultant production downtime is occurring due to water and sediment in the air supply. Videojets, sleevers, casers, Eagles, robots, and more use air and electricity to operate. Dirty and wet air is as bad for the equipment as low voltage and "noisy" electrical systems.
Water and oil separators and filters are a low cost solution to these ongoing maintenance, repair and replacement problems. The equipment-size filters and separators are totally overwhelmed by the lack of area-size separators in the air systems. There are also automatic, low-point, water removal devices available for placement at strategic points in each area.
Automatic air cutoffs tied into equipment on/off controls can also be purchased and installed on air using equipment as needed. These automatic cutoffs have a very short payback time and from then on you are making money.
Every piece of air using equipment in all the plants can be checked and each piece of equipment will show the effects of moisture and sediment damage. We do not track the damage caused nor the production downtime caused by the air supply problems, but if we did, I am certain it would be far more than the one-time cost of the solution.
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About the Author: Larry Bush has been an electrician for 47 years, and in maintenance management for 22 years. Download his new e-Book "Maintenance Policy and Procedures Manual" !!Please copy this article onto your websites, just keep all links and credits in place. Thank You